1. Field of the Invention
This invention relates to indicating controls and in particular to indicating controls for use in devices, such as microwave ovens, having rotatably adjustable mechanisms, such as the power level control means of such microwave ovens.
2. Description of the Prior Art
In U.S. Pat. No. 1,953,812 of George F. Lincks et al, a set of electric cut-outs are provided with fuse carriers having mounted thereto a pinion. A rack is provided for simultaneously actuating the pinions.
In U.S. Pat. No. 2,575,856 of Paul Ware, a spiral tuning device is shown for use with a television appliance, or the like, having a tuning shaft operating the tuning mechanism of the television receiver and carrying a translucent dial. On the face of the dial is provided a scale in the form of a seven-turn spiral and behind the dial is a small indicator lamp which is constrained to move along a vertical track by a sliding member having one edge in the form of a rack gear. Rotation of the shaft to adjust the television receiving mechanism rotates the scale correspondingly and causes a corresponding movement of the indicator lamp to eliminate the corresponding point on the scale spiral.
Albert E. Hedger, in U.S. Pat. No. 2,108,335, shows a radio tuning control having a manually adjustable knob connected to a rack having driving association with a pinion of the radio mechanism. Also connected to the knob is a flexible strip guided in an inclined guide to provide an indication of the disposition of the knob and correspondingly, the tuning control of the radio.
George C. Pearce, in U.S. Pat. No. 2,782,403, shows a slotted switch position indicator wherein a rotatable knob is connected to a cam which moves an indicator plate having a plurality of slots in a guided path adjacent a front plate having a different plurality of slots so that at any one time only an aligned pair of slots is illuminated by means of a rearwardly adjacent lamp. The rotatable mechanism is directly rotated by rotation of the knob so as to provide a desired correlation between the disposition of the control and the indicator.
Frank J. Skwarek, in U.S. Pat. No. 2,921,270, shows an extended frequency range signal generator control mechanism utilizing rack and pinion means as well as cam means in controlling a signal generator.
Walter L. Cherry et al disclose, in U.S. Pat. No. 3,499,127, a thumb wheel type switch utilizing rack and pinion means provided with a rotatable switch-carrying drum. An actuating lever extends to externally of the housing and a rotating means is rotated as a function of the movement of the actuating lever along a prescribed path.
Harold L. Purdy discloses, in U.S. Pat. No. 3,639,706, a reciprocating switch mechanism with improved thumb wheel actuator including a rack and pinion structure. A pair of gears are provided which are rotated to engage a stationary bar to move a carrier along the bar with the other gear moving the movable bar along the stationary bar a shorter distance than the carrier moves so as to move a slide a correspondingly shorter distance.
In U.S. Pat. No. 3,916,368, Herman D. Post et al show a positive motion fader device wherein a pair of potentiometers having rotary output shafts are mounted on a support. A first flexible steel strip is convoluted about a wheel associated with one of the potentiometers, and in reverse direction, about a wheel associated with the other of the potentiometers. A second similar strip is also convoluted in opposite directions about the wheels. A slider is connected with one of the strips and is guided in a slot so as to cause linear displacement of the strip elements in equal and opposite rotary movements of the wheels and output shafts of the potentiometers.
Junzo Tanaka et al, show in U.S. Pat. No. 3,978,305, a microwave oven control having signalling windows which are suitably illuminated by means of shutter mechanisms for controlling passage of light rays therefrom.